Updated simplified Chinese translations

Change-Id: I78e20de5fd84da2ede8a16f822935656293fafc8
fix for NPE
05-02 16:33:15.074 E/AndroidRuntime(15155): java.lang.NullPointerException
05-02 16:33:15.074 E/AndroidRuntime(15155): at com.android.mms.ui.MessageUtils.getAttachmentType(MessageUtils.java:438)
05-02 16:33:15.074 E/AndroidRuntime(15155): at com.android.mms.ui.MessageItem.onItemLoaded(MessageItem.java:329)
05-02 16:33:15.074 E/AndroidRuntime(15155): at com.android.mms.util.PduLoaderManager.run(PduLoaderManager.java:206)

Change-Id: I9734340d158c10b5b1f767abe2f4ada963874fd6